I have a question in regards to Xpath, which is something that I am very experienced at. I am doing an assignment where I am supposed to invert all the elements so that the sub elements inside of the Music tag becomes attributes and so that the attributes become sub elements.
Is it possible to do this using Xpath, and how should I got about it? Or is it better to write a DTD of the XML file and write a solution in Xquery?
My XML looks like this:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<music>
<song genre="rocknroll" album="1134" artist="249" id="11992"><name>The Sound of Silence</name><nr>1</nr></song>
<song genre="rocknroll" album="4329" artist="932" id="34311"><name>Material Girl</name><nr>2</nr></song>
<song genre="hardrock" album="5293" artist="1167" id="54312"><name>Paradise City</name><nr>1</nr></song>
<song genre="classic" album="7002" artist="156" id="78340"><name>La Primavera</name><nr>1</nr></song>
<artist id="249" isband="yes">Simon and Garfunkel</artist>
<artist id="932" isband="no">Madonna</artist>
<artist id="1167" isband="yes">Guns N'Roses</artist>
<artist id="156" isband="no">Antonio Vivaldi</artist>
<album issued="1964" id="1134" label="Columbia Records">Wednesday Morning, 3 AM</album>
<album issued="1984" id="4392" label="Sire Records">Like A Virgin</album>
<album issued="1988" id="5293" label="Geffen Records">Appetite for Destruction</album>
<album issued="2004" id="7002" label="Naxos Records" performers="Wiener Philharmoniker">Le Quattro Stagioni</album>
</music>
Thanks in advance for any help.
XPath can only select nodes in the input tree, or compute new atomic values (like strings and numbers). It cannot construct a new tree. For that you need XSLT or XQuery.
Writing a DTD might be useful for other reasons, but it won't make it any easier to produce the required XSLT or XQuery code for this problem.
Related
I am being given XML that looks like this:
<?xml version='1.0' encoding='UTF-8'?>
<singleton-list>
<fizzbuzz>
<amountId>123</amountId>
<countryId>456</countryId>
<action>Overwrite</action>
</fizzbuzz>
</singleton-list>
However, the outer-most element (in this case, singleton-list) will be different each time, and will be one of many different values. For instance I might get another XML message that looks like this:
<?xml version='1.0' encoding='UTF-8'?>
<aggregateList>
<fizzbuzz>
<amountId>123</amountId>
<countryId>456</countryId>
<action>Overwrite</action>
</fizzbuzz>
</aggregateList>
I'm trying to write an XPath that selects the fizzbuzz out of each message I receive, regardless of what the outer-most element is (singleton-list, aggregateList, or otherwise).
I think I could do something involving a wildcard, but I'm not sure if asterisks have special meaning in XPath or if I'm going about this the wrong way.
My best attempt at an XPath to do this selection is:
/*/fizzbuzz
Is this correct or is there a better way to do this?
either you can use //fizzbuzz or /*/fizzbuzz.
I want to use XPath to select the sub tree containing the <name>-tag with "ABC" and not the other one from the following xml. Is this possible? And as a minor question, which keywords would I use to find something like that over Google (e.g. for selecting the sub tree by an attribute I would have the terminology for)?
<root>
<operation>
<name>ABC</name>
<description>Description 1</description>
</operation>
<operation>
<name>DEF</name>
<description>Description 2</description>
</operation>
</root>
Use:
/*/operation[name='ABC']
For your second question: I strongly recommend not to rely on online sources (there are some that aren't so good) but to read a good book on XPath.
See some resources listed here:
https://stackoverflow.com/questions/339930/any-good-xslt-tutorial-book-blog-site-online/341589#341589
For your first question, I think a more accurate way to do it would be://operation[./name[text()='ABC']].And according to this , we can also make it://operation[./name[text()[.='ABC']]]
This is my first post here. I have just started working with Ruby and am using REXML for some XML handling. I present a small sample of my xml file here:
<record>
<header>
<identifier>oai:lcoa1.loc.gov:loc.gmd/g3195.ct000379</identifier>
<datestamp>2004-08-13T15:32:50Z</datestamp>
<setSpec>gmd</setSpec>
</header>
<metadata>
<titleInfo>
<title>Meet-konstige vertoning van de grote en merk-waardige zons-verduistering</title>
</titleInfo>
</metadata>
</record>
My objective is to match the last numerical value in the tag with a list of values that I have from an array. I have achieved this with the following code snippet:
ids = XPath.match(xmldoc, "//identifier[text()='oai:lcoa1.loc.gov:loc.gmd/"+mapid+"']")
Having got a particular identifier that I wish to investigate, now I want to go back to and select and then select to get the value in the node for that particular identifier.
I have looked at the XPath tutorials and expressions and many of the related questions on this website as well and learnt about axes and the different concepts such as ancestor/following sibling etc. However, I am really confused and cannot figure this out easily.
I was wondering if I could get any help or if someone could point me towards an online resource "easy" to read.
Thank you.
UPDATE:
I have been trying various combinations of code such as:
idss = XPath.match(xmldoc, "//identifier[text()='oai:lcoa1.loc.gov:loc.gmd/"+mapid+"']/parent::header/following-sibling::metadata/child::mods/child::titleInfo/child::title")
The code compiles but does not output anything. I am wondering what I am doing so wrong.
Here's a way to accomplish it using XPath, then going up to the record, then XPath to get the title:
require 'rexml/document'
include REXML
xml=<<END
<record>
<header>
<identifier>oai:lcoa1.loc.gov:loc.gmd/g3195.ct000379</identifier>
<datestamp>2004-08-13T15:32:50Z</datestamp>
<setSpec>gmd</setSpec>
</header>
<metadata>
<titleInfo>
<title>Meet-konstige</title>
</titleInfo>
</metadata>
</record>
END
doc=Document.new(xml)
mapid = "ct000379"
text = "oai:lcoa1.loc.gov:loc.gmd/g3195.#{mapid}"
identifier_nodes = XPath.match(doc, "//identifier[text()='#{text}']")
record_node = identifier_nodes.first.parent.parent
record_node.elements['metadata/titleInfo/title'].text
=> "Meet-konstig"
I have the following XML:
<ArrayOfStationStatus xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" autopagerMatchedRules="1">
<StationStatus ID="20" StatusDetails="To the platform due to planned maintenance work.">
<Station ID="20" Name="Bermondsey"/>
<Status ID="NS" CssClass="Closed" Description="No Step Free Access" IsActive="true">
<StatusType ID="2" Description="Station"/>
</Status>
</StationStatus>
</ArrayOfStationStatus>
And would like to select StationStatus nodes that contain a particular phrase in the Name attribute. It's important that I select SationStatus nodes.
This is the xpath I have come up with but it's not correct:
/ArrayOfStationStatus/StationStatus[contains(lower-case(child::Station/#Name),lower-case('phrase'))]
EDIT::::::::
I just solved it! This is the code I needed:
/ArrayOfStationStatus/StationStatus[child::Station[contains(lower-case(attribute::Name),lower-case("Ac"))]]
Well I managed to solve it people! Here is the solution, in this case I'm looking for the phrase 'Ac' as you can see
/ArrayOfStationStatus/StationStatus[child::Station[contains(lower-case(attribute::Name),lower-case("Ac"))]]
Also remember
lower-case(
is only available in xpath 2.0 (Dimitre Novatchev)
Lets say i have the following form data instance in my view.xml:
<xhtml:html xmlns:xhtml="http://www.w3.org/1999/xhtml"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:xxforms="http://orbeon.org/oxf/xml/xforms"
xmlns:exforms="http://www.exforms.org/exf/1-0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<xhtml:head>
<xforms:instance id="instanceData">
<form xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<fruits>
<fruit>
<fruit-name>Mango</fruit-name>
</fruit>
<fruit>
<fruit-name>Apple</fruit-name>
</fruit>
<fruit>
<fruit-name>Banana</fruit-name>
</fruit>
</fruits>
</form>
</xforms:instance>
</xhtml:head>
I want to select all the fruit names from the above instance.
I tried the following ways but it always selects the first fruit.
instance('instanceData')/fruits/fruit[*]/fruit-name
instance('instanceData')/fruits/fruit/fruit-name
instance('instanceData')/fruits/fruit[position()>0]/fruit-name
Please provide a way to overcome this in XPATH
try this
"//fruit-name"
It shall find all fruitnames wherever they are in the document hierarchy.
If you want to select all the <fruit-name> from the instance instanceData (<xforms:instance id="instanceData">) that looks like the one you have in your question, the following should do it:
instance('instanceData')/fruits/fruit/fruit-name
If this doesn't work, one common reason is that you have a default namespace declaration in the document that contains your instance, like: xmlns="http://www.w3.org/1999/xhtml". If you have this, you need to undo that default namespace declaration on where you declare the instance, with:
<xforms:instance xmlns="" id="instanceData">
(And if this is the issue, my advice is not to use default namespace declarations. Ever. Instead declare xmlns:xhtml="http://www.w3.org/1999/xhtml" and use the xhtml prefix everywhere.)
First:
It may be a typo any way to point out you xml has wrong node ending
<service>
Second:
your XPATH is very much valid but when you parse it out you need to iterate over the result set as like its a sequence of node and not a single value.
e.g) in JDOM :< Element.selectObject Vs selectSingleNodes Vs selectAsArray kind.
In your XForms you need to iterate over the resultset to get the list of fruits.
if you want only fruit names then you could try
instance('instanceData')/fruits/fruit/fruit-name/text()